1. Field of the Invention
The present invention relates generally to the fields of immunology and cancer therapy. More specifically, the present invention relates to a system utilizing interaction of electromagnetic pulses or ultrasonic radiation with nanoparticles to enhance anti-cancer drug delivery in solid tumors and uses of such a system.
2. Description of the Related Art
Many promising therapeutic agents have been proposed for cancer therapy for the past two decades. Their potential is proven in numerous preclinical studies. However, limited success has been achieved in solid tumor therapy. The presence of physiological barriers to drug delivery in tumors substantially limits efficacy of the anti-cancer drugs. To penetrate into cancer cells in a solid tumor, therapeutic agents have to pass through blood vessel wall, interstitial space, and cancer cell membrane. Penetration of anti-cancer drugs through these physiological barriers is poor especially for the most promising macromolecular therapeutic agents such as monoclonal antibodies, cytokines, antisense oligonucleotides, and gene-targeting vectors.
Methods have been reported for delivery of anti-cancer drugs with low molecular weight in solid tumors. Many of them are based on selective delivery of particles loaded with the drugs in tumors. It has been demonstrated that particles coated with a surfactant have prolonged circulation time and selectively accumulate in tumors because of increased leakage of tumor vasculature in comparison with the normal one. These long-circulating particles avoid rapid clearance by reticuloendothelial system. This approach is referred to as "passive" delivery of particles in tumors.
The "active" delivery is based on attachment of long-circulating particles to antibodies directed against antigens in tumor vasculature. Results of studies on animals bearing tumors derived from human cancer cells demonstrate feasibility of active delivery of anti-cancer drugs to tumor vasculature. These antibodies and short peptide sequences can be used for targeting anti-cancer drugs in patients.
The prior art is deficient in the lack of effective means of enhancing the delivery of anti-cancer drugs (especially macromolecular ones) from tumor blood vessels into cancer cells with minimal damage to normal tissues. The present invention fulfills this long-standing need and desire in the art.